Double apron drafting arrangement for spinning machines

ABSTRACT

The cradle is mounted with respect to the apron rolls and delivery rolls such that a lap formation on the bottom delivery rolls causes the cage to automatically pivot away from the delivery rolls so as to prevent further feeding of the roving. The cradle avoids any pressure being imposed on the bottom apron which might otherwise cause breakage of the apron.

United States Patent Lattion [451 Oct. 10, 1972 [54] DOUBLE APRONDRAFIING 2,696,026 12/1954 Noguera...; ..19/255 ARRANGEMENT FOR SPINNING2,717,425 9/1955 Noguera ..19/255 MACHINES 2,810,938 10/1957Rulon-Miller et-al....l9/266 X [72] Inventor: Andre Lama, wintenhur,Switzep 2,896,270 7/1959 Young et al. ..19/255 land FOREIGN PATENTS 0RAPPLICATIONS Assi8nee= Rieter Machine Works 524,886 8/1940 Great Britain..19/255 tetthur, swltzerland 807,372 6/1951 Germany ..19/255 [22]Filed: July 28, 1969 Primary Examiner-Dorsey Newton [21] Appl' 8451161Attorney-Kenyon and Kenyon Reilly Carr & Chapin [30] Foreign ApplicationPriority Data ABSTRACT July 26, 1968 Switzerland ..11572/68 The cradleis mounted with respect to the apron rolls and delivery rolls such thata lap formation on the bot- [52] US. Cl ..19/255 tom delivery r0115causes the cage to aummai-ically [51] Int. Cl. ..D0lh 5/86 pivot a y mth deliv y r l s so as to pr ent [58] Field of Search ..19/255, 256,254, 266, 267, r h r f ing f he roving. The cradle avoids any 19/244,253 pressure being imposed on the bottom apron which might otherwisecause breakage of the apron. [56] References Cited 8 CI 5 Drawingfigures UNITED STATES PATENTS 2,206,432 7/ 1940 Schofield ..19/255P'A'TE'N'TEDncr 10 m2 SHEET 1 [IF 2 FIGI //NVE1\'TOR. NDRE LATTIONDOUBLE APRON DRAFTING ARRANGEMENT FOR SPINNING MACHINES This inventionrelates to a double apron drafting arrangement for spinning machines.More particularly, this invention relates to a double apron draftingarrangement for automatically stopping drafting in response to lapformation.

In using double apron drafting arrangements it has been known to utilizea cradle for guiding the aprons into close vicinity of the nip of a pairof delivery rolls. However, the danger exists in the heretofore knownarrangements in that in the case of a lap formation on the bottomdelivery roll, the bottom apron is choked with increasing lap size sothat the bottom apron becomes subsequently blocked. As the bottom apronroll keeps driving and as the cradle in working position is rigidly heldrelative to the bottom apron roll, and due to the pressure exerted onthe bottom apron by the lap being formed, breakage of the bottom apronscan occur.

In order to prevent bottom apron breakage, double apron draftingarrangements have been provided'with a detachable top apron cradle. Insuch arrangements, the cradle has been supported by the bottom apron andhas been shiftable from a working position to a certain idle positionand back, the bottom apron being exposed openly in this movement. Adisadvantage of this known device is that in case of lap formation onthe bottom delivery roll adjacent to the aprons, the top apron cradlemust be turned around the longitudinal axis of the bottom apron roll andbe taken off while the lap must also be eliminated. This is due to thefact that the pressure of the cradle pressure axle, still rigidly heldby the support and pressure arm, against the bottom apron causes defectsof the bottom apron if the process continues. Furthermore, in order totake off the cradle, a locking mechanism between the guide bridge of thetop apron and the guide rail of the bottom apron must be unlocked first.

Accordingly, it is an object of this invention to create a double aprondrafting arrangement with a'cradle for bottom and top aprons whichautomatically eliminates the pressure exerted on the bottom apron if lapformation occurs on the bottom roll of the delivery roll pair followingthe aprons.

It is another object of this invention to automatically release thepressure between the aprons of a double apron drafting arrangement inresponse to a lap formation.

It is another object of the invention to pivot the cage of a doubleapron drafting arrangement away from the delivery rolls.

Briefly, the invention provides a double apron drafting arrangement fora spinning machine with a cradle for guiding top and bottom aprons intoclose vicinity of a nip of a pair of delivery rolls. This cradle issupported by the bottom apron roll and is pivotable around thelongitudinal axis of the bottom apron roll from a working position to anidle position and back. In addition, the cradle which tensions bothaprons is, in its working position, secured against tilting downwardlyfrom the drafting zone plane by a support and against tilting upwardlyfrom the drafting zone plane by a holding means. The holding means isconstructed to release the cradle under a pressure exerted against thebottom apron caused by a lap formation on the bottom delivery roll sothat the cradle by forcing the holding means automatically turns intothe idle position if lap formation occurs.

These and other objects and advantages of the invention will become moreapparent from the following detailed description and appendedclaimstaken in conjunction with the accompanying drawings in which: FIG.1 illustrates a cross-sectional view of a double apron draftingarrangement on a support and pressure arm with a cradle for the bottomand top aprons in working position according to the invention;

FIG. 2 illustrates a cross-sectional view of the double apron draftingarrangement of FIG. 1 with the cradle for the bottom and top aprons inan idle position;

FIG. 3 illustrates a cross-sectional view of a modified double aprondrafting arrangement with a split cradle;

FIG. 4 illustrates a cross-sectional view of the drafting arrangement ofFIG. 3 in an idle position; and

FIG. 5 illustrates a perspective view of a cradle according to theinvention.

Referring to FIG. 1, a drafting arrangement for a spinning machine whichis constructed as is known for drafting a roving 1 includes a pair oftake-in rolls 2,3 which define a pre-drafting zone 4with a top apronroll 6 and a bottom apron roll 7. In addition, a main drafting zone isprovided in the path of the roving I and is defined by the apron rolls6,7 a top apron 8, a bottom apron 9 and a pair of delivery rolls 10, 1l.

The bottom apron roll 7 which is aknurled roll supports a cradle 5 anddrives the bottom apron 9 about a bottom apron guide rail 12 at thefront part of the cradle 5 in the draft direction. The top apron 8 isdriven by the bottom apron 9 and moves around the top apron roll 6 whichis a pressure roll and is driven by the apron 8. Also, the top apron 8moves around a top apron guide rail 13 at the front part of the cradle5.

The top take-in roll 2 and the top delivery 10 are rigidly guided bypressure saddles 14, 15 respectively, saddle 14 being connected rigidlyto a distributor 16 and saddle 15 to a distributor 17. The distributors16, 17 are commonly supported via an element (not shown) in a supportand pressure arm 18 by a pivot pin 19. Also rigidly connected todistributor is a middle pressure saddle 20 which in working position hasa recess 21 which contacts the axle 22 of the top apron roll 6. Thesaddle 20 is also turnable as the distributor 17 pivots around the pivotpin 19. One double apron drafting arrangement is arranged to the rightand to the left of the support and weighting arm 18. For purposes ofsimplicity, however, only one of the two double apron drafting systemsis shown.

The pressure saddle 20 surrounds axle 22 with its recess 21 from the topand with a leg 23 at the front in the draft direction. As the axle 22 isthus secured against pivoting around the bottom apron roll 7 along apath defined by a pivoting circle 24 passing through the center of theaxle 22, the cradle 5 is secured against tilting downwardly from thedrafting zone plane. To the rear, the pressure saddle 20 covers the axle22 with the recess 21 over a short distance only, ending at an end point24 situated outside the pivoting circle 24. Furthermore, a spring hoop25 is secured to the underside of the pressure saddle 20 and extendsrearwardly therefrom parallel to the pivoting circle 24 and is bent intothe draft direction below the drafting zone plane in order to take upthe axle 22 as described further in the following.

If, as shown in FIG. 2, laps 26 form on the bottom delivery roll 11, apressure is exerted against the top delivery roll 10 and against thebottom apron 9 guided into close vicinity of the nip of the pair ofdelivery rolls 10, ll. Owing to the upward tiltability of the cradle 5around the longitudinal axis of the bottom apron roll 7 the front partof the cradle 5 will turn away upwardly under the pressure exertedagainst the bottom apron 9 by the lap formation. While the lap on bottomdelivery roll 11 increases in size and thus increasingly lifts the frontpart of cradle 5, axle 22 is pushed backwards with respect to thedrafting direction, is forced over the end point 24 of the recess 21 inthe saddle 20 and slips backwardly out of the recess 21. The axle 22then moves along the pivoting circle 24 after slipping out of the recess21. As the front part of the cradle 5 is lifted, the top delivery rollis also lifted and turns the pressure saddle around the pivot pin 19along a pivoting circle S passing through the end point 24 into thedirection of the pivoting circle S A along which axle 22 turns. Axle 22and end point 24 of recess 21 thus tangentially slide past each other inopposite directions. If a lap forms on bottom delivery roll 11, thefront part of cradle 5 automatically tilts upwardly from the draftingzone plane and tears off the roving 1 between the front part of thecradle 5 and the nip of the pair of delivery rolls 10, 11. Furtherincrease of the lap on the bottom delivery roll 1 1 thus is suppressedautomatically.

Referring to FIG. 2, axle 22 has slipped out of the rebess 21 ofpressure saddle 20 completely due to the growing lap formation 26 on thebottom delivery roll 11. Cradle 5 which supports the axle 22 has pivotedbackwardsaround the longitudinal axis of the bottom apron roll 7 and isheld by virtue of the spring hoop catching the axle 22. The spring hoop25 keeps the top apron 8 which is brought into the vicinity of thetake-in bottom roll 3 due to the pivoting motion of cradle 5, fromcontacting the take-in bottom roll 3. The supply of roving I to the pairof delivery rolls 10, 11 is interrupted. As axle 22 has slipped out ofthe pressure saddle' 20, the top apron roll 6 no longer exerts pressureagainst the bottom apron roll 7 and the roving l is no longer drawn inbetween the top apron 8 and the bottom apron 9. The roving l which isstill drawn in by the pair of take-in rolls 2, 3 drops onto the machineframe or onto a cover plate (both not shown) where sufficient room isavailable for depositing any roving material 1 still drawn in overprolonged periods until the lap is eliminated.

Referring to FIGS. 3 to 5 wherein like parts are designated with likereference characters as above, the cradle consists of a part 27 whichguides the top apron 8 and of a part 28 which guides the bottom apron 9.The part 27 has, as seen in the draft direction, at the front lateralwalls 29 extending downwardly and provided with recesses 32 (only onebeing shown). The part 27 is supported by pins 33 (only one being shown)extending outwardly from the lateral walls of the part 28 into therecesses 32. These parts 27, 28 are detachably connected at the front bythe recesses 32 and the pins 33. The back, with respect to the draftdirection, of guide part 27 is supported by the axle 22 of the top apronroll 6. The arrangement consisting of the two guide parts 27, 28 canpivot around the longitudinal axis of the bottom apron roll 7 as theguide part 28 is supported by the bottom apron roll 7. A spring hoop 30,together with the spring hoop 25, is fixed to the support and pressurearm 18 by means of a holding screw 31. The spring hoop 30 surrounds theaxle 22 in the front and from below with respect to the draft direction.If the pressure arm 18 is lifted, the spring hoop 30 will carry the axle22 upwardly while the guide part 27 is lifted from guide part 28 sincetheir connection, as mentioned above, becomes detached. The lateralwalls 29 which extend downwardly, are guided by the pin 33 during thelowering of the support and pressure arm 18. In their working position,the guide parts 27, 28 are held together at the front part of the splitcradle by the connecting elements mentioned be fore and at the back partby the pressure exacted from the pressure roll saddle 20 on the axle 22of the top apron roll 6. In the idle position, the two guide parts 27 28are held together at their back parts by the spring hoop 25 receivingthe axle 22 and pressing the top apron roll 6 in the direction of thebottom roll 7, whereas at their front part the aforementioned connectingelements maintain the connection (FIG. 4).The support of the pressuresaddle 20 on the axle 22 in the working position corresponds to the oneshown in FIG. 1. Owing to the support of the lateral guide element walls29 on guide part 28, the split cage undergoes the same phases ofmovement as the cradle mentioned above in the case of lap formation onthe bottom delivery roll 1 1. Thus, in case of lap formation, the splitcradle as shown in FIG. 4 is forced over the end point 24 of thesupporting recess 21 of the pressure saddle 20, automatically tilts backand the lap formation is interrupted.

The holding means for holding the cradle 5 in place until a detrimentallap formation occurs is thus constituted primarily by the pressuresaddle 20 and the recess 21 with the accompanying end point 24 andsecondarily by the distributor 17 and support arm 18. The spring hoop 25serves to limit the pivoting of the cradle 5 so as not to contact thetake-in rollers 2, 3.

What is claimed is:

1. In a drafting arrangement,

a pair of apron rolls,

a pair of aprons mounted about said apron rolls on opposite sides of adrafting plane,

a cradle mounted on one of said apron rolls and supporting said apronsin tension thereon,

a pair of delivery rolls adjacent said aprons, and

a pressure saddle disposed to pivot about a pivot point located betweenthe plane of said delivery rolls and the plane of said apron rolls, saidpressure saddle having the other of said apron rolls disposed therein todefine a working position of said other apron roll and being pivotalabout said pivot point in a direction towards said delivery rolls inresponse to a predetermined movement of one of said delivery rolls fromthe other to permit said other apron roll and said cradle to pivot aboutsaid one apron roll in a direction away from said pressure saddle intoan idle position, said one delivery roll being located on the same sideof said drafting plane as said pressure saddle.

2. In a double apron drafting arrangement for spinning machines, thecombination of a pair of delivery rolls forming a nip in a drafting zoneplane; a bottom apron roll; a cradle supported on said bottom apronroll, said cradle being pivotally mounted about the longitudinal axis ofsaid bottom apron roll between a working position and an idle position;a top apron and a bottom apron supported and tensioned on said cradlefor guiding into close vicinity to said nip with said cradle in saidworking position; a top apron roll having an axle mounted in saidcradle; a pressure saddle surrounding said axle from above and in frontwith respect to the draft direction to within a pivoting circleextending through the axis of said top apron roll for securing saidcradle in said working position against tilting downwardly from saiddrafting zone plane, and in back to an endpoint situated above saidpivoting circle for releaseably holding said cradle in the workingposition of the drafting arrangement against tilting upwardly from saidplane, said pressure saddle being pivotally connected to a support andpressure arm to pivot about a center point located between the 1 planepassing through the axes of said delivery rolls and the plane passingthrough the axes of said apron rolls, said arm being shiftable upwardlywith respect to said drafting zone plane whereby upon occurrence of alap formation on the bottom roll of said delivery rolls, the lap abutssaid bottom apron to simultaneously move said axle of said top apronroll past said endpoint and pivot said cradle about said longitudinalaxis of said bottom apron roll into said idle position to preventfurther lap formation.

3. In a double apron drafting arrangement as set forth in claim 2further including a pair of take-in rolls and a spring hoop extendingfrom said saddle to the drafting zone plane parallel to and above saidpivoting circle, said spring hoop being fixed to said saddle and bent atthe free end thereof into the draft direction to partially surround saidaxle of said top apron roll whereby said hoop holds said cradle in saididle position against further upward tilting and out of contact withsaid take-in rolls.

4. In a double apron drafting arrangement as set forth in claim 2wherein said cradle includes a first guide part guiding said top apronand supported on said top apron roll, and a second guide part guidingsaid bottom apron and supported on said bottom apron roll, said guideparts being detachably connected to each other at the front with respectto the draft direction.

5. In a double apron drafting arrangement as set forth in claim 4further including a first spring hoop connected to said support andpressure arm surrounding said axle of said top apron roll in the frontand from below with respect to the draft direction, and a second springhoop extending off from said saddle to said drafting zone plane parallelto and above said pivoting circle, said second spring hoop being fixedto said saddle and bent at the free end thereof into the draft directionto hold said guide parts together in said idle position while acting inthe direction of said bottom apron roll.

6. in a double apron drafting arrangement for spinning machines, thecombination of a pair of delivery rolls forming a nip in a drafting zoneplane, a bottom apron roll, a cradle supported on said bottom apronroll, said cradle being pivotally mounted about the longitudinal axis ofsaid bottom apron roll between a working position and an idle position,a top apron and a bottom apron supported and tensioned on said cradlefor guiding into close vicinity to said nip with sald cradle in workingposition, a top apron roll mounted in said cradle, a support forsecuring said top apron roll and cradle in said working position againsttilting downwardly from said drafting zone plane, and means forreleasing said cradle and top roll from said support to allow tilting ofsaid cradle upwardly from said plane under a pressure against saidbottom apron exerted by a lap formation on the bottom roll of saiddelivery rolls, said support being pivotally connected to said means topivot about a point located between the plane of the axes of saiddelivery rolls and the plane of the axes of said apron rolls towardssaid delivery rolls in response to the occurrence of a lap formation onsaid bottom delivery roll whereby said cradle is tilted into said idleposition.

7. In a double apron drafting arrangement as set forth in claim 6wherein said top apron roll has an axle supported in said cradle, andwherein said support comprises a pressure saddle surrounding said axlefrom above and in front with respect to the draft direction to within apivoting circle centered in the axis of said top apron roll and in backto an endpoint situated outside said pivoting circle, and said meansincludes a support and pressure arm connected to said saddle, said armbeing shiftable upwardly with respect to said drafting zone plane.

8. In a double apron drafting arrangement as set forth in claim 7further including a pair of take-in rolls and a spring hoop, said springhoop being fixed to said saddle and bent to partially surround said topapron roll whereby said hoop holds said cradle in said idle positionagainst further upward tilting and out of contact with said take-inrolls.

1. In a drafting arrangement, a pair of apron rolls, a pair of apronsmounted about said apron rolls on opposite sides of a drafting plane, acradle mounted on one of said apron rolls and supporting said aprons intension thereon, a pair of delivery rolls adjacent said aprons, and apressure saddle disposed to pivot about a pivot point located betweenthe plane of said delivery rolls and the plane of said apron rolls, saidpressure saddle having the other of said apron rolls disposed therein todefine a working position of said other apron roll and being pivotalabout said pivot point in a direction towards said delivery rolls inresponse to a predetermined movement of one of said delivery rolls fromthe other to permit said other apron roll and said cradle to pivot aboutsaid one apron roll in a direction away from said pressure saddle intoan idle position, said one delivery roll being located on the same sideof said drafting plane as said pressure saddle.
 2. In a double aprondrafting arrangement for spinning machines, the combination of a pair ofdelivery rolls forming a nip in a drafting zone plane; a bottom apronroll; a cradle supported on said bottom apron roll, said cradle beingpivotally mounted about the longitudinal axis of said bottom apron rollbetween a working position and an idle position; a top apron and abottom apron supported and tensioned on said cradle for guiding intoclose vicinity to said nip with said cradle in said working position; atop apron roll having an axle mounted in said cradle; a pressure saddlesurrounding said axle from above and in front with respect to the draftdirection to within a pivoting circle extending through the axis of saidtop apron roll for securing said cradle in said working position againsttilting downwardly from said drafting zone plane, and in back to anendpoint situated above said pivoting circle for releaseably holdingsaid cradle in the working position of the drafting arrangement againsttilting upwardly from said plane, said pressure saddle being pivotallyconnected to a support and pressure arm to pivot about a center pointlocated between the plane passing through the axes of said deliveryrolls and the plane passing through the axes of said apron rolls, saidarm being shiftable upwardly with respect to said drafting zone planewhereby upon occurrence of a lap formation on the bottom roll of saiddelivery rolls, the lap abuts said bottom apron to simultaneously movesaid axle of said top apron roll past said endpoint and pivot saidcradle aboUt said longitudinal axis of said bottom apron roll into saididle position to prevent further lap formation.
 3. In a double aprondrafting arrangement as set forth in claim 2 further including a pair oftake-in rolls and a spring hoop extending from said saddle to thedrafting zone plane parallel to and above said pivoting circle, saidspring hoop being fixed to said saddle and bent at the free end thereofinto the draft direction to partially surround said axle of said topapron roll whereby said hoop holds said cradle in said idle positionagainst further upward tilting and out of contact with said take-inrolls.
 4. In a double apron drafting arrangement as set forth in claim 2wherein said cradle includes a first guide part guiding said top apronand supported on said top apron roll, and a second guide part guidingsaid bottom apron and supported on said bottom apron roll, said guideparts being detachably connected to each other at the front with respectto the draft direction.
 5. In a double apron drafting arrangement as setforth in claim 4 further including a first spring hoop connected to saidsupport and pressure arm surrounding said axle of said top apron roll inthe front and from below with respect to the draft direction, and asecond spring hoop extending off from said saddle to said drafting zoneplane parallel to and above said pivoting circle, said second springhoop being fixed to said saddle and bent at the free end thereof intothe draft direction to hold said guide parts together in said idleposition while acting in the direction of said bottom apron roll.
 6. Ina double apron drafting arrangement for spinning machines, thecombination of a pair of delivery rolls forming a nip in a drafting zoneplane, a bottom apron roll, a cradle supported on said bottom apronroll, said cradle being pivotally mounted about the longitudinal axis ofsaid bottom apron roll between a working position and an idle position,a top apron and a bottom apron supported and tensioned on said cradlefor guiding into close vicinity to said nip with said cradle in workingposition, a top apron roll mounted in said cradle, a support forsecuring said top apron roll and cradle in said working position againsttilting downwardly from said drafting zone plane, and means forreleasing said cradle and top roll from said support to allow tilting ofsaid cradle upwardly from said plane under a pressure against saidbottom apron exerted by a lap formation on the bottom roll of saiddelivery rolls, said support being pivotally connected to said means topivot about a point located between the plane of the axes of saiddelivery rolls and the plane of the axes of said apron rolls towardssaid delivery rolls in response to the occurrence of a lap formation onsaid bottom delivery roll whereby said cradle is tilted into said idleposition.
 7. In a double apron drafting arrangement as set forth inclaim 6 wherein said top apron roll has an axle supported in saidcradle, and wherein said support comprises a pressure saddle surroundingsaid axle from above and in front with respect to the draft direction towithin a pivoting circle centered in the axis of said top apron roll andin back to an endpoint situated outside said pivoting circle, and saidmeans includes a support and pressure arm connected to said saddle, saidarm being shiftable upwardly with respect to said drafting zone plane.8. In a double apron drafting arrangement as set forth in claim 7further including a pair of take-in rolls and a spring hoop, said springhoop being fixed to said saddle and bent to partially surround said topapron roll whereby said hoop holds said cradle in said idle positionagainst further upward tilting and out of contact with said take-inrolls.